Check if the new version is compatible with your previous save files. Major version jumps (e.g., 0.6 to 0.7) can sometimes break older saves.
According to the developer, , the 0.7 series of updates (including v0.7.0.p4b) typically includes:
Official updates and the latest "bugfixed" versions are primarily released through the Loki Art Patreon. Jogo VN - Exchange Student [v0.7.0.p1a] Pc//Android
Bug fixes and "remakes" of existing scenes to improve visual quality.
Go to your device settings and allow installations from unknown sources to install the APK file.