Kahoot is a great site to use for formative assessment. I often use Kahoot for a fun review activity my class before a quiz or a test. Source: www.Kahoot.it
Canva is a website that allows the user to create a quality poster with relatively simple effort. It offers many free features that students can use to create a poster for presentations. Source: https://www.canva.com
Four corners: This technique stimulates student learning through movement and discussion, and it can also be used as a formative assessment. Students are presented with a controversial statement or are asked a question. In each of the four corners of the classroom, an opinion or response is posted. Students express their opinion or response by standing in front of one of four statements, and then talking to others about why they have chosen their corner. Four Corners promotes listening, verbal communication, critical thinking, and decision-making.
Exploringbytheseatofyourpants is a website that allows a class to connect with professionals in their respective fields. Classes set up a skype/google hangout call with the professionals to participate in their research or experiments. This gives an alternate option for field trips that may be more difficult to organize. Source: http://www.exploringbytheseat.com
Google Timelapse is global, zommable video that lets you see how the Earth has changed over the past 32 years. One for each year from 1984 to 2016. It offers students to research environment-related project, studying how Earth has changed over the years. Source: https://earthengine.google.com/timelapse/