Any reliable SMS app that leverages Twilio

Any reliable SMS app that leverages Twilio

we are now using Zoho one with 3 team members and hoping to add a couple more to the team soon. IS there a reliable sms tool we can use as a team to. send appointment reminders on workflow and appointments and secondly to do bulk messaging.

we have a twilio number and we don't want a new number as clients know our number. its quite frustrating staying up nights to get something that will work but. nothing so far or they are rediculously expensive for our budget.

Any ideas please because its very frustrating at the moment as we're losing business due to this.