I happily purchased this app in 2013. As an dual national of Iran, having grown up in the US, I can not read Farsi (and my verbal skills are elementary at best). This app, with nearly 100% English capability, made independent movement about Tehran so easy. The ability to drop pins, like corner stores, snap a photo of it, add a title, was a great unexpected bonus and all without the need of a SIM card. I deleted the app after I left (its huge and for obvious reasons). In 2014, for reasons I was never able to figure out, I had to repurchase the app, which had increased in price. The 2nd time round, I was not happy with some interface changes that caused imo unnecessarily long option pathways. The 3rd time, 2015, I thankfully did not have to repurchase, however, it had not been updated. This was hugely problematic as Tehran is an ever-expanding megatropolis with numerous new highways, rerouting each year. Even with its steep price, I would gladly pay again to use it should the company keep it updated.
M---RAD about Sygic Iran: GPS Navigation, v13.1.2