documentation update 34 (#545)

* Play Store badge

* improved badges layout

* improved descriptions

docs/installation.md

@@ -1,40 +1,58 @@
 # Traditional T9 Installation Guide
+Traditional T9 has two variants: "lite" and "full". The "lite" version is the standard one, available on all app stores and GitHub, while the "full" version is only on GitHub.
 
-## Devices that allow installing APKs
+The "lite" version is meant to take minimum storage space and for fast upgrades over the air. The APK is about 2 Mb and contains no language files. It downloads them on demand from GitHub. But excluding that, it uses no Internet at all.
+
+The "full" version has all language files bundled in the APK, making it about 70 Mb. It is a good choice when working offline and for devices where network traffic is expensive or very slow. It is also the recommended choice on low-end or 3G devices, because they may not be able to keep a stable Internet connection under a heavy load.
+
+_The "lite" version is available since release 34.0. Before that, the APK always included all available languages, meaning all older versions were always "full"._
+
+## Devices with Google
+On devices with Google Services, the recommended way of installing Traditional T9 is from the Play Store. New releases usually appear one working day after the release on GitHub.
+
+_Google Play Store uses the .aab file format, which is incompatible with the .apk format in all other sources. This means you must first uninstall Traditional T9 if you want to switch to or from the Play Store._
+
+## Devices without Google
+If your device does not have Google services but allows installing APKs, you can use an alternative app store or manually download and install the APK from Github. Each variant has pros and cons and it is a matter of a personal preference which one to choose.
 
 ### From F-Droid
-The recommended way of installing is using F-droid. It will automatically manage downloads and keep TT9 up-to-date. The downside is new versions may become available as late as two weeks after the official release on Github.
+Just like Play Store, F-droid will automatically manage downloads and keep Traditional T9 up-to-date. The downside is new versions may become available as late as two weeks after the official release on GitHub.
 
 If you don't have F-droid, get the official F-droid APK from https://f-droid.org/ and install it. For more info, refer to the [installation instructions](https://f-droid.org/en/docs/Get_F-Droid/).
 
 After you get F-droid working, just open it, search for "Traditional T9" and install it.
 
 ### From Uptodown
-Uptodown is similar to F-droid. You can get Traditional T9 easily, but new versions become available at least a week after the Github release.
+Uptodown is another Play Store alternative, very similar to F-droid. What is different is, the new releases appear within 1-2 days after the GitHub release.
 
 If you don't have the Uptodown Store, download and install it from [uptodown.com](https://uptodown-android.en.uptodown.com/android).
 
 ### From GitHub
-If you would like to run the latest version as soon as it is released, go to the GitHub [Releases section](https://github.com/sspanak/tt9/releases). Then either download the APK on your phone or download it on a computer and transfer it to the phone. After that, just click or tap to install. If custom APK installation is enabled, it will just work. If not, your phone may show a popup, asking you to grant the installation permission, before proceeding.
+GitHub is the primary release platform. All new releases are published there first. Also, it is the only place where you can find the "full" version. However, it is not an application store, which means you will have to manually check for and install updates. And, it requires a bit more technical skill than the other options.
+
+To obtain TT9 from GitHub, go to the [Releases section](https://github.com/sspanak/tt9/releases). Then either download the APK on your device or download it on a computer and transfer it to the device. After that, just click or tap to install. If custom APK installation is enabled, it will just work. If not, Android may show a popup, asking you to grant the installation permission, before proceeding.
 
 In some cases, installation permissions are disabled by default, but you can usually enable them by going to Android Settings → Apps → Settings → Security, then enabling "Installation from unknown sources".
 
 _The setting name or location may be different on different Android versions. Nevertheless, a quick Google search for your phone make and model, should point you in the right direction._
 
-## Devices that do not allow installing APKs or do not display TT9 after installation
+## Limited or Locked Phones
 Some manufacturers prefer to lock their devices and disallow installing or enabling (or both) third-party keyboards or apps in general. It is likely to reduce the complaints "my phone isn't working", caused by the manually installed apps. The problem has been discussed [here](https://github.com/sspanak/tt9/issues/455) and [here](https://github.com/sspanak/tt9/issues/198).
 
-Examples of such phones include some Kyocera models, for example, the DuraXV Extreme+, ZMI Z1, all models by Sonim, and so on. On Sonim XP3800 and XP5800, there is an "Install from Unknown Sources" option, but since the November 2022 update, the phone will still refuse to install APKs unless they have been sent to and approved by Sonim.
+Examples of such phones include some Kyocera models, notably, the DuraXV Extreme+, ZMI Z1, all models by Sonim, and so on. On Sonim XP3800 and XP5800, there is an "Install from Unknown Sources" option, but since the November 2022 update, the phone will still refuse to install APKs unless they have been sent to and approved by Sonim.
+
+On such limited phones, your only option is to download the APK on a computer, then connect the phone to the computer and install using a program called "adb" (Android Debug Bridge). If you feel confident using the command line, follow the instructions below.
 
 ### Prepare Your Computer
-To install TT9 on such locked devices, you will have to connect your phone to a computer and use a program called "adb" (Android Debug Bridge). If you feel confident using the command line, follow the instructions below.
-
 First, go through the [adb quick setup](https://www.xda-developers.com/install-adb-windows-macos-linux/). If you need more detailed info, see the [developer documentation](https://developer.android.com/tools/adb).
 
-### Prepare the Phone
-If you have successfully enabled the Developer Mode while setting up ADB, proceed to the next step.
 
-On older phones, the Developer Mode cannot be enabled by clicking the build number. Instead, it is done by dialing a special code which usually looks like this: `*#*#XXXX#*#*`, where XXXX is some number. Find the code for your phone and dial it. Usually, phones from the same company, running the same Android version, share the same code. For example, the code for Sonim XP3800 also works on XP5800.
+After you are done, download the APK of your choice from the GitHub [Releases section](https://github.com/sspanak/tt9/releases).
+
+### Prepare the Phone
+If you have successfully enabled the Developer Mode while setting up ADB, skip this step and proceed to the next one.
+
+On older phones, the Developer Mode cannot be enabled by clicking the build number as described in the ADB setup guide. Instead, it is done by dialing a special code which usually looks like this: `*#*#XXXX#*#*`, where XXXX is some number. Find the code for your phone and dial it. Usually, phones from the same company, running the same Android version, share the same code. For example, the code for Sonim XP3800 also works on XP5800.
 
 _The procedure on your phone may be entirely different from the methods described above, but Google is your friend. It should be fairly easy to find how to do it unless your phone is completely locked._
 

docs/user-manual.md

@@ -1,5 +1,5 @@
 # Traditional T9
-This manual explains how to configure and use Traditional T9 in different scenarios. For installation instructions, please consult the [Installation Guide](https://github.com/sspanak/tt9/blob/master/docs/installation.md) on GitHub. Finally, you may want to check out the [main repository page](https://github.com/sspanak/tt9), which includes all source code, a developer's guide, the privacy policy, and supplementary documentation.
+This manual explains how to configure and use Traditional T9 in different scenarios. For installation instructions and information about the "lite" and "full" versions, please consult the [Installation Guide](https://github.com/sspanak/tt9/blob/master/docs/installation.md) on GitHub. Finally, you may want to check out the [main repository page](https://github.com/sspanak/tt9), which includes all source code, a developer's guide, the privacy policy, and supplementary documentation.
 
 ## Initial Setup
 After installing, first, you need to enable Traditional T9 as an Android keyboard. To do so, click on the launcher icon. If you need to take any action, all options besides Initial Setup will be disabled, and there will be a label: "TT9 is disabled". Go to Initial Setup and enable it.
@@ -13,6 +13,11 @@ If your phone does not have a hardware keypad, check out the [On-screen Keypad s
 Predictive Mode requires a language dictionary to be loaded to provide word suggestions. You can toggle the enabled languages and load their dictionaries from Settings Screen → [Languages](#language-options). In case, you have forgotten to load some dictionary, Traditional T9 will do it for you automatically when you start typing.
 For more information, [see below](#language-options).
 
+#### Notes for low-end phones
+Dictionary loading may saturate low-end phones. When using the TT9 "lite" version, this will cause Android to abort the operation. If loading takes more than 30 seconds, plug in the charger or ensure the screen stays on during loading.
+
+You can avoid the above by using the "full" version instead.
+
 #### Notes for Android 13 or higher
 By default, the notifications for newly installed apps are disabled. It is recommended to enable them. This way you will get notified when there are dictionary updates, and once you choose to install them, TT9 will show the loading progress. New updates are released at most once a month, so you don't have to worry about getting too much spam.
 
@@ -248,7 +253,7 @@ On some devices, TT9 may remain invisible, no matter what you do. In such cases,
 
 **Long explanation.** The reason for this problem is Android is primarily designed for touchscreen devices. Hence, it expects you to touch the text/number field to show the keyboard. It is possible to make TT9 appear without this confirmation, but then, in some cases, Android will forget to hide it when it must. For example, it may remain visible after you have dialed a phone number or after you have submitted text in a search field.
 
-For these reasons, in order to stick with the expected Android standards, the control is in your hands. Just press a key to "touch" the screen and keep typing.
+For these reasons, to stick with the expected Android standards, the control is in your hands. Just press a key to "touch" the screen and keep typing.
 
 #### On the Qin F21 Pro, holding 2-key or 8-key turns up or down the volume instead of typing a number
 To mitigate this problem, go to Settings → Appearance, and enable "Status Icon". TT9 should detect Qin F21 and enable the settings automatically, but in case auto-detection fails, or you have disabled the icon for some reason, you need to have it enabled, for all keys to work properly.