Problem with the concept

[Igor]

Hello,

Sorry for delay, we'll check this but it will take some time.

[Maryna Brodina]

Hello! Sorry for a late reply.
1) Before sync check if localStorage variable is set (let it be synchronized for example). If it's set - do not sync, if it's not set - do sync. After sync is done set this variable to avoid iteration of this operation.
2) If the user closes the app or restart device - localStorage and Web SQLite won't disappear.
3) SQLite and localStorage are the best solution. You can also store in files, but it's much more complicated.