Have a client (actually, customer of my client) has requested the ability to send SMS text messages from within their app for notifications. I know about Twilio but I’m curious if there are other options available.
One more monkey wrench in this mix: This particular customer is in Peru but they sell their software all over the world so it needs to be something global.
Before someone throws it out there, the phone company does not have email to SMS capabilities (or at least that’s their claim.
https://www.clickatell.com/products/platform/ Haven’t used them, so can’t recommend, but worth a look.
I’ve used Cellsynt, works great. Their API has scheduling and other stuff too 
https://www.cellsynt.com/en/sms/api-integration
I successfully used http://www.2sms.com since they had multiple alternatives to send an SMS. I was able to FTP a file to their site and they send it for you (given you have an account).
Using twilio for both inbound and outbound messages.
Check the availability https://www.twilio.com/sms/coverage as many countries are not available for inbound sms. Most of our users are OK with receiving messages from US-numbers but not sending “international” messages TO US-numbers. We have about 15 different inbound numbers in various countries.
The first XOJO app I wrote was for SMS messaging and I have been using www.clickatell.com for a number of years as the SMS provider. Excellent service and uptime and more interfaces/API’s than you can shake a stick at!. There pricing as far as I can tell is also very competetive as you don’t need a monthly subscription and can bulk buy message credits in advance.
I prefer MessageBird. Pricing is ok and their API and API documentation is really good. Someone should build a Xojo library delivering to MessageBird …
We used Clickatell for a while and had issues. We moved to Twillo and are loving it.
Hi Hal Gumbert,
Do you still have code for posting the url using clickatell’s api.
I use “post” and it keep giving a error http 405 Method cannot be used.
Please advice.
Would be nice if we had a simple to use WhatsApp API, being charged per usage rather than monthly fee for numbers you’re not using anyway.
I buy credits in bulk, they last for ever, don’t have to do the monthly thing.
Which API are you using Paul ?
I use the HTTP API, I don’t need any call back or data back, and can query individual messages if required.
[quote=393034:@Benny Lee]Hi Hal Gumbert,
Do you still have code for posting the url using clickatell’s api.
I use “post” and it keep giving a error http 405 Method cannot be used.
Please advice.[/quote]
It’s super easy just call this url replacing the square bracket tags with your info. It’ll return data back which you can parse. Here’s info for the Error Codes: https://archive.clickatell.com/developers/api-docs/message-status-codes/
I’d share code, but my code in FileMaker. 
http://api.clickatell.com/http/sendmsg?user=[username]&password=[password]&api_id=[api_id]&MO=1&from=[your_clickatel_phone_num_starting_with_1]&to=[to_phone_num_starting_with_1]&text=[message]I’d still suggest using Twillo.
As long as you dont need to control the number that shows up as the sender you can use the email gateways. Every provider in the states I know at least maintains a way to send an email to an sms message. For example for an AT&T customer you just email 1112223333@txt.att.net or for Verizon its 1112223333@vtext.com. There are lists out there of every provider. If you can setup the app to send email then you can also send texts to almost everyone by just asking for the provider and number and then choosing the correct email server address from a list.
You dont get to control who it says it comes from, the number looks random or sequential or something I dont know, but it is free and has worked quite well for me in a couple of specific circumstances where they didnt want to pay for the ability and also were sending to corporate phones that they all knew were on one or 2 different services.