Determining the most powerful countries can be subjective and depends on various factors including military strength, economic prowess, technological advancement, diplomatic influence, and cultural impact. As of my last update in January 2022, some of the most commonly recognized powerful countries include:

United States: Historically known for its strong military, technological innovation, and economic dominance, the United States remains a global superpower.

China: With the world's largest population and rapid economic growth, China has been increasingly asserting itself on the global stage economically, technologically, and militarily.

Russia: Despite economic challenges, Russia maintains significant military power, especially in terms of nuclear capabilities, and plays a crucial role in global geopolitics.

Germany: As the largest economy in Europe and a leader in technological innovation, Germany holds considerable influence within the European Union and on the global economic stage.

United Kingdom: Despite its smaller size compared to other global powers, the UK remains influential in diplomacy, finance, and military matters, particularly through its historical alliances and membership in international organizations.

France: France possesses a strong military, holds a permanent seat on the United Nations Security Council, and plays a leading role in European politics and diplomacy.

Japan: Despite limitations imposed by its pacifist constitution, Japan is a technological powerhouse and holds considerable economic influence in Asia and globally.

India: With a rapidly growing economy, a large population, and increasing military capabilities, India is emerging as a key player in global affairs.

Brazil: As the largest country in South America and an emerging economic power, Brazil wields significant influence in regional politics and international diplomacy.

South Korea: With advanced technology and a strong economy, South Korea plays a crucial role in global trade and is an important ally in the Asia-Pacific region.

It's important to note that power dynamics can shift over time due to various factors such as economic changes, political developments, and technological advancements.

Predicting the most used apps in 2024 might involve some speculation, but based on trends and patterns, certain apps could maintain or grow their popularity:

Social Media Platforms: Apps like Instagram, TikTok, and Snapchat might continue to be among the most used, especially among younger demographics.

Messaging Apps: WhatsApp, Facebook Messenger, and WeChat are likely to remain dominant for communication purposes.

Video Streaming Services: Netflix, YouTube, and possibly newer contenders in the streaming space could continue to see high usage.

E-commerce Platforms: Amazon, Alibaba, and other e-commerce platforms may see increased usage as online shopping continues to grow.

Gaming Apps: Mobile gaming apps like Fortnite, PUBG Mobile, and Garena Free Fire could maintain their popularity, along with emerging titles.

Collaboration Tools: Apps like Zoom, Microsoft Teams, and Slack might remain essential for remote work and communication.

Fitness and Wellness Apps: With a growing focus on health and wellness, apps like Fitbit, MyFitnessPal, and Headspace could see increased usage.

Finance Apps: Banking apps, investment platforms like Robinhood, and cryptocurrency wallets may continue to gain traction.

News and Information Apps: Apps offering personalized news feeds like Flipboard, Google News, and Apple News might remain popular for staying informed.

Education Apps: With the rise of online learning, educational platforms like Coursera, Udemy, and Duolingo could continue to see significant usage.

These predictions are based on current trends, but the landscape of popular apps can change rapidly due to technological advancements, shifts in consumer behavior, and the emergence of new players in the market.