iZettle - portable, cheap card readers for i-phones and androids

I have been looking for a card reader for a while for my practice. I can take cash and cheques, but have noticed that not all my clients carry cash or have a cheque book,. Bank transfers are good, but necessitate too much vigilance on my part to make sure the right people have paid the right amount. All the readers I have seen were cumbersome and expensive, attached to one place only and demanded a merchant account. I wanted something light, portable and cheap, that I could use in all my clinics, for a minimal outlay. In the States last year I found what I wanted called Square, one that attached to my iPad and worked wirelessly, but sadly that system isn't yet available in the UK.
Recently wireless became available in both my clinics, and at the same time I got an email from iZettle offering me a free card reader. See...
https://www.izettle.com/gb

So I signed up, got the app, the card reader arrived, and off I went. Really, that easy. The app is very straightforward, I gave my bank details and transferred £1 to iZettle to set up my transfers. The £1 came back into my account, and I started to take payments..
Pros - the card reader is light, easy to transport,and fits onto my iPad (works on any smartphone or tablet apparently). The app is easy to use with minimal fuss. You don't need a merchant account as the cash goes from iZettle to you, in my experience within a week of payment. You can use it wirelessly or over the Internet. iZettle themselves have responded to all my enquiries promptly and sensibly, and send me emails when I take a payment and when the money is transferred to my account.
Cons - the big one is that with the card reader I have (now £20 unless you get the free offer I got) the client needs to have a smartphone. When you take the payment, a text is sent to the client's phone with a web address and a code, they then go to the web address and confirm the payment. If you are paying for your card reader anyway, rather than pay for the £20 one I would buy the £49 chip-and-pin version which would remove the need for the client to have a smartphone. The second point against iZettle is the 2.75% per transaction fee.
Personally, iZettle works for me. It makes it much easier for my clients to pay, costs very little, and I can use it wherever I want. I probably will change to the chip-and-pin reader soon, just to make it even easier.
 I want to help my clients to pay me as easily as possible, after all!