If you’re a frequent traveler and you need to change SIM cards wherever you go, I recommend the mobile apps Coins.ph and Mobile Recharge. I alternate between the two mobile apps as each has unique services to offer.
I signed up with Coins.ph a few years back and completed the profile verification steps quickly. I knew Coins.ph dealt with Bitcoins primarily and they only extended their services to include mobile top-up not only for Philippine mobile numbers but also for international numbers. I have tried their Buy Load feature with my Philippine mobile numbers and also for my Vietnamese and Cambodian SIM cards and the top-up was successful.
You can top up your international mobile numbers with Mobile Recharge as well. In fact, M-Recharge mobile app is mainly for that purpose. I have used it in the past to top up my Malaysian and Thailand SIM cards. The only reason I keep Coins.ph as an alternative for mobile top-up is that the available denominations Mobile Recharge top-up are higher compared to that of Coins.ph. The minimum amount for mobile top-up with Mobile Recharge is at $10 which you can conveniently purchase using your PayPal account. Coins.ph does not have the option to purchase via PayPal as users would have to top up their Coins.ph Wallet first before they can purchase using their Coins.ph account.