I know PowerApps SQL gateway does not currently support MYSQL. I was wondering if it would be possible to connect MYSQL as a linked database to a MSSQL 2012 server. Then connect the PowerApps SQL Gateway to the MSSQL server and pull data from MYSQL through the link. I've got this most of the way setup, but the Gateway doesn't seem to want to pull from the MYSQL database. The SQL connection setup gives me "Error the tables didn't load correctly" when I put in my Windows credentials for the MSSQL server. If I put in the credentials for the local MYSQL it times out and never saves.
MYSQL to MSSQL link
http://www.c-sharpcorner.com/article/create-a-linked-server-mysql-to-sql-server/
PowerApps SQL Gateway
https://powerapps.microsoft.com/en-us/tutorials/gateway-reference/
We recently purchased Layer2 Cloud connector for a separate OneDrive related project. I'm going to try using that to get this data into a Sharepoint list or something similar to use with PowerApps.