First of all, we chose not to say which app is better or worse. We believe that preference involves a lot of personal taste (e.g., do you prefer a male or female voice? longer or shorter meditations? etc.) and each app has its strengths and weaknesses.
With that in mind, we decided to suggest some of the meditation apps we tested and liked the most, with a quick summary of each one.
In our tests, we found many points we would like to comment on, but to keep this post from getting too long and unproductive, we believe the best way forward would be to download the ones that interest you most and try them for yourself!
Meditation apps in Portuguese
Vivo Meditação
Vivo Meditação is centered around Satyanatha, an experienced Brazilian monk. It has an introductory track with 13 items that is free. Since these are shorter audio/video clips (averaging 3-4 minutes), you can do 2 items per day and fit them into our week of testing.

Strength: Has extensive meditation content, including various meditations specifically for sleep
Weakness: Limited free content.
Rating: 4.8 ⭐️
Rating: 4.0 ⭐️
Installs: 1,000,000+
Lojong
Unlike Vivo Meditação, this app has several meditation teachers, specialists in each area. It has an introductory Mindfulness track with the first meditations free by professor Dr. Daniela Sopezki.

Strength: Has extensive meditation content.
Weakness: Limited free content.
Rating: 4.9 ⭐️
Rating: 4.9 ⭐️
Installs: 1,000,000+
Meditation apps in English
Headspace
A pioneer in meditation apps, it features a 10-day introduction to meditation track that is free. Additionally, it's the only app that considers itself both a meditation and sleep app! It has an entire section of the app dedicated to sleep.

Strength: Features "sleepcasts" which are longer audio experiences for you to listen to and relax before bed.
Weakness: We didn't have a bad experience ourselves, but there are several reports of people complaining about technical issues with the app.
Rating: 4.0 ⭐️
Rating: 4.6 ⭐️
Installs: 10,000,000+
Calm
One of the most well-known meditation apps in the world. It features a 7-day introductory meditation track. Like Headspace, it has a specific section for sleep, with stories for you to listen to and relax before bed.

Strength: Easy to use, and features content from famous people.
Weakness: Limited free content.
Rating: 3.5 ⭐️
Rating: 4.5 ⭐️
Installs: 50,000,000+
Insight Timer
Unlike other meditation apps that have a main meditation teacher, or a group of specialists, this app resembles a social network, being more of a community of meditation practitioners.

Strength: Has the best reviews among meditation apps, and due to its community nature, where many people can create their own meditations, the variety and availability of meditations is very large compared to most other apps.
Weakness: Does not have an introductory meditation track like other apps. We only recommend it for those who already have some meditation practice.
Rating: 5.0 ⭐️
Rating: 4.9 ⭐️
Installs: 10,000,000+
*Data last updated in November 2019.
