[I apologize, I only have experience with Apple products but I'm sure the apps work with all smart-devices.]
I was in the same place with my parents 60th birthday bash. I wanted something I could use on all platforms like Facebook, Instagram & Text. Here's the final product...
I used my two favorite apps to create my evite. They're easy to use and since I didn't have time to stage a photo session and hire a graphic designer this was a simple solution.
Like I said, "I didn't have time" which translates into last minute planning. I dug into my iPhotos and pulled them out of the virtual cloud. This pic had potential but it was too cluttered.
I took a blank screenshot on my iPad Mini and pulled it into "Cut Me In" then I selected this pic. Now comes the work... erasing the clutter. [It was actually therapeutic.]
Above is the final result. This came after I shrunk the image and pulled it to the corner. Ahh it looks better already. Next step is to add the party information and a few elements of design. I imagined the two of them having a conversation about turning sixty.
Below is an image of their conversation bubbles from the A+ Signature app. I completed the rest of the evite in this app. [Tip: there's a lot of fonts so keep it minimal, possibly two.]
The final invitation was fun, informative and easy to use on multiple platforms. Notice how I reflected the colors from my Mom's 2014 Seahawks Championship jersey. That's their favorite team.