ShareX Portable

Considering there are numerous types of applications on the market, you no longer need to be a PC expert to perform a wide range of actions on your computer, such as taking snapshots, uploading them online so you can share them with friends, compare checksums or tweak images.
The best thing is that you can get all of these functions from a single application called ShareX Portable, and you do not even need to install it (since it is a portable utility, it can run out of the box wherever you store it).

Take snapshots and upload them

Due to its intuitive interface, you can start taking screenshots in no time, and you get complete control over the type of capture that will be made: full screen, rectangle, rounded rectangle, open window, ellipse, triangle, diamond, polygon or freehand.
Alternatively, you can also drag and drop a file from your PC then upload it to a hosting service of your choice, depending on the document you are processing: you can choose image uploaders (such as Imgur, ImageShack or TinyPic), text uploaders (like PasteBin or Pastee) or a more general service, such as Dropbox, Google Drive, RapidShare, Mega or a FTP server.
However, you need to keep in mind that most of these services first need to be authorized within your account before you can use them.

Intuitive image editor

ShareX Portable can also be used to enhance images before uploading them online, as users can stamp graphic or text watermarks, crop, resize, rotate or skew them, as well as adjust the brightness, contrast or colors.
Additionally, several filters are also supported, such as pixelate, emboss, Gaussian blur, shadow, sharpen or edge detect.

Conclusion

To wrap it up, ShareX Portable is a flexible application that can basically meet all your requirements in terms of capturing images and uploading files online. Moreover, it can come in handy when you want to check your monitor for stuck pixels or compare checksums.