- If you're on Android 2.2 and up, Google Play will give you Gospel Library 2.6.15. (No longer receiving content updates.)
- If you're on Android 2.3 and up, Google Play will give you Gospel Library 3.3.4. (Content updates will end at the end of 2017.)
- If you're on Android 4.0 and up, Google Play will give you Gospel Library 4.2.3. (Content updates will continue for the foreseeable future.)
- If you're on Android 4.2 and up, Google Play will give you the latest version of Gospel Library (currently 4.3.1). (Content updates will continue for the foreseeable future.)
Only the newest versions of Gospel Library will continue to receive the newest content (new general conferences, magazines, devotionals, curriculum, editions of the scriptures, etc.). This is because the content format changes with major app releases to support new features. (As an analogy, you can think of this as switching content from PowerPoint files to Word files. The new format allows us to do more, but is not compatible with the old app. For a little while, as users transition from the old version of the app to the new, the content team produces both (continuing the analogy) a PowerPoint and a Word file of each content item, but eventually, the old file type is phased out to focus resources on providing more and better content in the new format.)
If your device doesn't support the newest Gospel Library, don't feel obligated to buy a new device. The Church doesn't require members to use the newest technology to study the gospel – Gospel Library is provided as a tool for those who are able to benefit from it. If you are on an older device, you can access the newest content by browsing LDS.org or by downloading PDFs to your device. If you don't have a smart device at all, the Church continues to provide scriptures and other core content in print format.
If you are considering purchasing an Android device to use Gospel Library or other Church apps, check the Android version. I wouldn't recommend any Android version below Android 4.4, which is the minimum supported Android version for new Church apps (like LDS Media Library) and will likely become the minimum supported Android version for Gospel Library and LDS Tools the next time there's a major update. Newer versions of Android beyond 4.4 will provide a smoother experience and will last farther into the future, but will generally cost more. For reference, the current version of Android is Android 8.