Texting Blue lets a team share an existing iPhone number and send and receive iMessages from a browser or through an API. You connect your business number and install a lightweight extension on the iPhone. The site says no extra hardware or dedicated account is needed. It is operated by Interactive Marketing, s.r.o.
From the pricing section on texting.blue:
A 3-day free trial is available.
Linq provides managed numbers and a production API with group chats, rich media, iMessage apps and voice. Texting Blue runs on your own iPhone number and is built mainly as a shared inbox, with API access for power users. Its current Lite plan supports text only and caps volume at 100 messages a day. Images and calls are listed for future plans. Its site does not mention compliance certifications.
Small businesses that want several staff members to reply from one existing iPhone number, with light automation.
Texting Blue supports 20 of the 77 features compared on Linq Alternatives.