I understand that "proper English" is vague, but what I mean is, are adverbs to be avoided in scholarly writing? For example, let's say that I am wanting to publish an article in scholarly magazine for college English professors. Would the readers of that magazine generally look down upon a frequent use of adverbs as "fluff."

The reason I ask is because my English professor showed our class the "Hemingway Application." According to hemingwayapp.com, the purpose of the program is to make your writing "bold and clear." One of the ways it supposedly does this is highlighting the adverbs so that you can replace them with "verbs with force." So, what is the problem with adverbs, and what would be an example of a verb "with force?" Lastly, could you please use an example where an adverb is used, then replace it with a verb "with force."