Flat Icon Generator Beta can be used to generate Flat Icons with ease and can be exported as .png images.
Note: You will need to append the generated flat icon name with the extension of '.png' when saving the image file.
As of now, I have not covered the features extensively, but they are on my list and will be added soon.
Developed by Mr. Alien
Flat Icon Generator is Licensed Under Apache License v2.0
As far as the Redistribution goes, refer Point 4 "Redistribution"
You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions:
You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License.
Please DO NOT use this for any Commercial Purposes
Information of the License for the plugins used can be found on their respective Git Hub Pages...