Airtable spells out the rate limits for you right in their API documentation:
Airtable is not meant to be a back end for applications or supporting heavy API usage. If you’ve built your application to make multiple API requests or complex API requests in a single action, it will not be difficult to hit the 5 request/second limit.
I’d suggest looking at something like https://firebase.google.com, which is built for the purpose of supporting mobile applications.