These are some tips that helped people like you to speed up their learning curve:
enjoy it: attach positive emotions to the learning process. Learning does not have to be boring or stressful. You always remember what you live, what you feel and what you do if there is a strong emotion attached to it. And for effective learning this strong emotion has to be positive in order to remain in the long-term memory. If you are interested, read more about the importance of emotions for effective learning.
be consistent: plan some days in your calendar when you are going to practice with a native speaker of your target language. Consistency is key to improve in any skill.
surround yourself: immerse yourself with books, music, movies and activities in your target language. Disclaimer: my husband was learning Spanish while dancing salsa and listening to Spanish songs. Don't feel bad about making use of subtitles in a movie or in a YouTube video: they will help you to follow along and better understand the context if needed. I still do it with some English movies when the actors speak too fast or have a difficult accent.
travel: plan trips to Spain and countries in South America or participate to volunteering/interchange programs to these countries. There are also people who decide to have a non-permanent job in one of these countries.
strive for progress, not perfection: adults in particular tend to over-analyze or stress about their mistakes, thinking that the accent is not perfect or that there is zero understanding. This stress is what slows down progress. None of this matters in the long term: commitment is more important!
talk with real live humans: languages apps are great to learn new vocabulary, but they will never replace the emotions and care that a real human can give you. Combine the learning from language apps with the one given by a native speaker that can guide you through the process. You can have informal language exchanges, enroll in a course, or take classes online. If you have friends that speak Spanish, try to spend more time with them and ask them to speak in their language with you.
ask questions: never be afraid to ask a question about something you don't know or don't understand in Spanish. There are a lot of resources online that will give you an answer or you can simply send us a message with your doubts. Also, if you practice with a native speaker, don't forget to ask that person.
customize the learning to your needs: most of the time, people learn a language because they want to travel, work in a foreign country or simply for hobby. Whatever your motivation is, getting guidance on the things really important for you will speed up your learning. Let's say that you learn Spanish because you would like to feel more immersed when you go to South America. You will probably need to know how to ask for a good place to eat or how to ask for directions to get back to the place where you are staying. Learning all the animals or all the irregular verbs in the past form won't probably help you in the first place. While these are important to learn, it is also important to understand when it is the right moment to learn it in order to not waste time. This is something that a personal teacher can probably do better than a learning app.
don't get too attached to grammar: most people approach a ‘language as an object’. They can describe the language's rules, grammar and syntax, but they cannot use it. A language is like a living plant that needs consistency and care to grow. Use the language without being afraid of making mistakes (native speakers make a lot of mistakes too). Then you will refine the grammar and get better with time.
record your progress: this is something new that I tried with my students and they felt very motivated after looking at their improvements. Often, we just look at what there is still to learn instead of appreciating what it has already been done. Looking back at your progress can motivate you to continue, more than looking at all things still to be learned. One easy and simple suggestion is to use your phone to record yourself telling a story or presenting yourself in Spanish. Do it once a month and then re-watch your progress. I promise you will also have a lot of fun.
A language is not an object that you know, but it is something that you do.
Extra tip: if you speak a Latin language, then learning Spanish might result easier for you. Don't loose that opportunity to learn one of the most spoken languages in the world.