I kept finding more and more bugs with 1.2. The ± thing, a problem with equals followed by a parenthetical, echoing variables without arithmetic.
I believe all the bugs I currently know about are fixed. Plus, I fixed some performance issues in how fast an equation is solved (barely noticeable on most equations though). And I fixed the problem with the horizontal division bar and the bar over a rooted expression where they would disappear during a selection animation.
You can now copy an equation out of the calculator as an image and paste it anywhere that is accepting of images, such as email. Click and hold on the equation for half of a second and the copy bubble will appear when you let go.
The ± button works in front of numbers, variables, constants and it also will swap the sign of these types. Also in front of parentheses, and functions to negate the calculated value. Pressing the ± button after the close parenthesis of a parenthetical or a function will swap the sign of the whole expression.
Read This for more features added since 1.1.