Your iPad 1, even in 2015, the first 2010 iPad 1 was an early adpoter device that was severely underpowered THEN and with an iOS version that only lasted for one year before iOS upgrades/updates were halted.
The 1st gen of a brand new device category is always going to be a, sort of testbed.
The 1st gen Macintosh, in 1984, was very underpowered, when it was first introduced, compared to the technologies that were out there at that time.
While the iPad 1 is still useful, today in 2017, (I revived mine at the beginning of 2016) it is still a somewhat limited device with the much lower 256 internal RAM, the amount of background activities need to be kept to a minimum.
I just found out that my iPad 1 and iOS 5.1.1 supports AirPlay mirroring!
At least the first iPad had a CPU that ran at the full 1.0 Ghz frequency speed!
While the iPad 2 and 1st gen iPad Mini had double the RAM of the first iPad 1, at 512 MBs of RAM, Apple dynamically clocked the 1.0 CPU to run, nominally, at 800 Mhz with the iPad 2 and Mini performance CPU PEAK of 1.0 Ghz, if it needed it!
If you were/are still getting by on the 1st gen, 2010 iPad, newer iPads have come a long way way, especially since the introduction of the iPad Air and Pro models and even the current iPad Mini 4 is packed with much better/faster technology.
So, you are really missing out!
My wife and I still regularly use an iPad 2 and 3 even though I now own a large screen iPad Pro.
I'll get, at least, another 4 years or more out of my current iPad Pro.