First make sure your device is running Android Lollipop ––version 5.0–– or later. Other reason Texpand may not work is if you have other conflicting third-party accessibility services in your device, try turning some of them off to find out which.
This happens if you have blue light filter app installed i.e those apps that dim the screen at night. For security reasons the Android platform will not let you press the "ok" button in the dialog that appears while trying to activate an accessibility service. To solve this problem turn off the blue light filter app temporarily then activate Texpand, after this you can continue to use the blue light filter app as usual.
Texpand only works on apps that use the standard input field provided by the Android SDK. For apps that uses specialized input fields Texpand may not work, unfortunately this problem is out of my scope of control.
The main reason for this is some phones have built in mechanism that kills background services. I have confirmed that Huawei phones have such built-in feature, but you can whitelist apps in the settings. Research if your phone has such feature and make sure your system or other apps aren't killing Texpand. Another reason that might cause similar problem is the battery optimization feature introduced on Android 6.0 if you are experiencing inconsistent experience with Texpand you can fix it by setting Texpand to not be battery optimized. Texpand version 1.7 will automatically ask you disable battery optimization (only for Texpand) click "yes" for a more reliable experience. If you are using older version of Texpand you will have to do this manually by going to settings.
Currently the only way to transfer phrases between devices is to back it up to your device storage or Google drive and importing it on other devices. For the future there is a plan to implement real-time sync between devices.
When you are planning to upgrade to Texpand PRO don't uninstall the free version of Texpand. Once the pro version of Texpand is installed it will prompt you to import your data from free version of Texpand, then it's highly recommended that you uninstall the free version of Texpand.
You can provide feedback or ask questions by going to Texpand's settings and in the "about" section click "send feedback". You can also ask questions in Texpand official twitter account.