It's a website so as long as you have a browser on your phone an inter-web connection you can access it 🙂
It takes a bit to make a profile, then add an address, THEN file a TM30 on someone at that address, save their data then search for it to export the PDF file that is the receipt of having filed a TM30 online, BUT it could be done on a phone.
You'll have to print that PDF somehow as you're supposed to keep it in your passport
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