The Bitcoin Jungle wallet uses Bull Bitcoin as an automatic off-ramp.

I've heard the Costa Rican banks are not Bitcoin-friendly and it's not easy for the locals to buy BTC (this may have changed though?), so I'm not sure how it works, they must have a local bank account to make SINPE payments to the merchants' accounts and a way to sell BTC for CRC (maybe via CAD using the liquidity from their Canadian business).