Bitcoin Testnet API that allows transaction lookup and submission of raw transactions

I’m looking for a well developed, maintained and stable API allowing to access bitcoin testnet. Something like Infura for Ethereum. Googling gives many results, but can somebody point me out what is really in use?
In the moment for me BlockCypher looks the best, but can I really trust it?
It would be nice if the API was free, but it not necessarily has to be.
Cheers