1) Google Trends  gives you real-time insights into the hot topics that people are searching for now.

I rarely use this as most of my clients have very specific needs and keywords but I guess some developers may find this useful.

2) Google Ads Keyword Planner allows you to discover new keywords and get search volume and forecasts.

I use this regularly at the start of a new website project. I enter what I think is a relevant keyword to get started and then run the tool to get a bunch of results. I then download this as a CSV file and open it up in Excel. In Excel I get rid of all the columns that I don't need and create a new one which is number of monthly searches divided by the numeric competition level. I then sort the whole table on this new column in descending sequence. This brings to the top the most useful keywords that are either high volume or have the least competition.

Strangely, I usually struggle to find this tool and Google seem to keep moving it as well which doesn't help!