Refining the mobile application

The services of an Android app developer are required. We need to redesign the mobile app. On some devices, when downloaded from Play Store, writes: “The app is not active for your device.”
When opened, a white screen lights up. What exactly was tested on: Lenovo TAB 2 A7-30DC Version Android 5.0.1 Firmware module communication
MOLY.WR8.W1449.MD.WG.MP.V1,2015/07/22 Core Version 3.10.54

General.
(1) the ability to select a photo from the device gallery
2) the tablet does not have a filter + it must be written that it is a filter
(3) remove door prices
(4) To make it possible to stretch the doors over all 4 corners + automatically pop-up magnifier, to define the boundaries more precisely
Doors.
5) You need to think about some protection from competitors (demo version of the application for 2 days). Use it through your personal account)
(6) Place doors of the same model but of different colours in a row. If more than 4 colors - it should be possible to scroll the product series (right-left)
+ there should be arrow signs, so it is clear that there are more doors in this row.
Our app (for iOS, too) is available.