You can use both applications and use the code to have free credits.
1st Option: My Taxi
1) Download the My Taxi Free app.
2) Sign up in less than 1 minute
3) Use the promotional code "isaac.cha1" in the Promotions section.
2nd Option: App Cabify
1) Download the free Cabify app.
2) Register in less than 1 minute
3) Use the promotional code "JESUSV2281" in the Promotions section and enjoy a coupon for your first trip.