First off, don't be too hard on yourself! Weight fluctuates. Have you recently changed your activity level or eating habits? The key to weight loss/maintenance is portion control. Exercise helps too, but the biggest contributor to weight gain is excess calories. Apps are good for helping you tally what you're eating and holding yourself accountable, but they are only as good as the information entered into them. The worst part is that aging definitely diminishes your metabolism, so it gets harder
I bought an elliptical a few years ago that I use at home. I also try to mix it up with other activities I can do with my family.
Good luck!