After having had my Skype number for more than 15 years, I opted to port the number to Vyke, and so far, I'm experiencing no real problems. I simply downloaded the Vyke app from the Play Store, and sort of followed the bread crumbs. Apparently Vyke can only port USA-based Skype numbers (which applied to me, fortunately). The process of porting the Skype number must be initiated by Vyke through my request to them - not the other way around.
Because my phone SIM uses a Thai phone number, the Play Store denominates any of my financial transactions in Thai Baht. So, when I decided to pay the annual $19.99 fee for the continued use of the old Skype number, I did this using the Vyke app, and discovered that this translated into an 800THB charge. Vyke uses its own formula for foreign exchange transactions, which I learned are nowhere near market rates. And payments for topping-up the account can be made either on the app, or via the Vyke website. I learned that it's preferable to use their website for this purpose, because the transactions are charged in USD - which is good for me, because I can make these payments using a USD credit card. Not sure if any of this is useful to others (who might have different circumstances), but I figured I'd share it anyway. Based on my brief check of the Vyke foreign exchange formula ($8.49 becomes 475THB using the app), I'll stick with the website for topping-up my account.
Once I had topped-up the account via their website, and the transaction was accepted by my credit card company, I very quickly noticed the updated account balance on my app. So I called a buddy in the US for a long-overdue conversation, and to test the functionality - which seemed fine, although I did notice a slight delay. Afterward, the balance on my Vyke app was reduced accordingly. The Vyke rates for calls to the US are 1.2c/minute, less than Skype was charging. And most importantly, now I can receive phone calls (and now, international text messages as well, which are supported by Vyke) from my US-based financial institutions.